Tribological Analysis and Design of a Modern Automobile Cam and Follower

Dr. Guangrui Zhu gained his PhD on engine valve train tribology at the University of Leeds, UK in 1988. He has worked in an industry-based R&D environment since then. He has published numerous journal and conference papers on journal bearings, trust bearings, mechanical seals, and valve trains. Professor Chris Taylor has researched in the area of lubrication for over 30 years, with engine tribology being a major theme in recent times.

• Series Editor's Foreword xiAuthors' Preface xiiiNotation 1Chapter 1 Introduction 5Part I Theoretical FormulationChapter 2 Kinematics and Dynamics of the Cam and Follower 112.1 Introduction 112.2 Kinematic analysis of a cam and domed flower pair 112.3 The load at the cam/follower interface 132.4 The solution procedure 152.5 References 15Chapter 3 Hydraulic Lash Adjuster 173.1 Introduction 173.2 Check valve closed 173.2.1 The dynamics of the plunger 173.2.2 The governing equation of the displacement 193.2.3 Numerical analysis 203.3 Check valve open 213.3.1 The dynamics of the plunger 213.3.2 The governing equation of the displacement 233.3.3 Numerical analysis 243.4 The numerical solution procedure 24Chapter 4 The Maximum Hertzian Stresses 254.1 Introduction 254.2 The contact geometry 254.3 The maximum Hertzian stress 274.4 The pressure distribution 274.5 The solution procedure 274.6 References 28Chapter 5 Asperity Interactions 295.1 Introduction 295.2 The asperity contact force 295.3 The real area of contact 295.4 The asperity contact functions 305.5 The solution procedure 305.6 References 31Chapter 6 The Oil Film Thickness 336.1 Introduction 336.2 The lubricant entraining velocity 336.3 The central and the minimum film thickness 356.4 The solution procedure 356.5 References 36Chapter 7 Friction and Power Loss of the Valve Train 377.1 Introduction 377.2 The friction of the cam and follower interface 377.2.1 The friction due to shear of the lubricant 377.2.2 The friction due to asperity contact 387.3 The friction of the follower and bush interface 387.3.1 The tilting of the follower 397.3.2 The friction model 417.4 The friction of the valve and guide interface 427.5 The friction of the valve stem and valve seal interface 437.6 Power loss of the valve train 437.7 The solution procedure 447.8 References 44Chapter 8 The Rotation of Follower 458.1 Introduction 458.2 The governing equation of the follower rotation 458.2.1 The Diving torque of the cam/follower interface 468.2.2 The resisting torque of the follower/bush interface 488.2.3 The resisting torque of the valve stem/plunger interface 498.3 The solution procedure 498.4 References 50Chapter 9 The Overall Solution Procedure and Input and Output Data 519.1 Introduction 519.2 Input data 519.3 The kinematic analysis 519.4 The analysis of the hydraulic lash adjuster 519.5 Estimating the initial value of the follower rotational frequency 529.6 The tribological analysis of the valve train 549.7 The friction torque of the camshaft and average power loss 549.8 The output data 54Chapter 10 An Example of the Tribological Analysis of a Valve Train 5710.1 Introduction 5710.2 Parameters of the intake valve train of the ZETEC engine 5710.3 Results of the tribological analysis 5910.4 A brief discussion of the results 5910.5 References 60Part II Experimental StudyChapter 11 Introduction to Experimental Study 8711.1 Preamble 8711.2 The background of the current experimental study 8811.3 The aim of the experimental study 8811.4 References 89Chapter 12 Test Apparatus and the Instrumentation 9112.1 Introduction 9112.2 The hydraulic lash adjuster 9112.3 The data acquisition system 9112.4 Monitoring the follower rotation 9312.5 Locating the cam position 9412.6 Sampling the torque of the camshaft 9412.7 References 95Chapter 13 Calibration of the Instrumentation and Commissioning Tests 9713.1 Introduction 9713.2 Calibration of the instrumentation 9713.2.1 The Calibration to the torque measurement system 9713.2.2 The parasitic friction of the test apparatus 9913.2.3 The calibration for monitoring the follower rotation 9913.3 Commissioning tests 10013.3.1 Improving the signal for the follower rotation10013.3.2 Tests at different camshaft rotational frequencies 10113.4 References 101Chapter 14 The Test Procedure 10314.1 Introduction 10314.2 The running-in of the valve train 10314.3 The loop test 10314.4 The duration test 10414.5 Tests at different bulk temperatures References 10514.6 References 106Chapter 15 The Data Processing 10715.1 Introduction 10715.2 The torque on the camshaft 10715.3 The rotational frequency of the follower 10715.4 The camshaft trigger signal 10815.5 References 109Chapter 16 Experimental Results and Discussions 11116.1 Introduction 11116.2 Experimental variables and the test condition 11116.3 Experimental results and discussions 11216.3.1 The friction torque and power loss of the valve train 11216.3.2 The rotational frequency of the follower 11316.3.3 Inspection of the cam and the follower 12116.4 Conclusions 12216.5 References 124Part III Correlation Of Theory And ExperimentsChapter 17 Introduction to Correlation of Theory and Experiments 127Chapter 18 The Experimental Evidence 129Chapter 19 The Theoretical Predictions 13119.1 Introduction 13119.2 Kinematics and dynamics 13119.3 The cam/follower interface 13119.4 The follower/bore interface 13219.5 The hydraulic lash adjuster 13319.6 The rotation of the follower 13319.7 References 133Chapter 20 The Comparison of Results and Discussions 13520.1 Introduction 13520.2 The input data of the model simulating the test conditions 13520.3 The results of comparison and discussions 13720.3.1 The average friction torque 13720.3.2 The instantaneous torque on the camshaft 14020.3.3 The instantaneous friction torque on the camshaft 14020.3.4 The average follower rotational frequency 14520.3.5 The instantaneous follower rotational frequency 14620.4 Conclusions 14920.5 References 149Chapter 21 Overall Conclusions 151Index 153